Technological problems in the application of large diameter channelled flux intensifiers for obtaining images by photon counting

A system study is presented of a microchannel plate image intensifier tube, coupled to a plumbicon camera tube for photon counting imagery purposes. The photon spectrum covers 120nm to 800nm. Performances have been evaluated of a structure with a proximity focusing image intensifier and of a structure with a magnetic focusing. In both cases this stage is followed by a curved microchannel plate delivering 0.2 million charges per detected photoelectron. This charge is accelerated in a proximity space to a luminescent screen, which is line-by-line analyzed by a plumbicon tube. Certain advantages of proximity focusing were found with regard to magnetic focusing. They include better detection efficiency, higher signal to noise level, absence of distortion, and external field insensitivity.